Barrier for closures



- FIG. I14

Nov. 19, 1968 G. v. MUMFORD I. 3; 111,65 1

BARRIER FOR CLOSURES Filed Oct. 31, 1966 2/ 24 FIG. 3

I INVENTOR. Games V. mm Peal:

BY 4, m1! 1 United States Patent 01 Rice 3,411,651 Patented Nov. 19, 1968 3,411,651 BARRIER FOR CLOSURES George V. Mumford, Toledo, Ohio, assignor to Owens-Illinois, Inc., a corporation of Ohio Filed Oct. 31, 1966, Ser. No. 590,909 13 Claims. (Cl. 21540) ABSTRACT OF THE DISCLOSURE An infestation barrier for lug-type closures on baby food and like containers, the barrier being comprised of a soft and resilient cellular plastisol aflixed to the closure skirt to substantially occupy the region disposed intermediate said skirt and container finish, downwardly of the gasket.

This invention relates to closures for bottles and jars; more particularly, it relates to an improvement in hermetic sealing closures.

The main concern of the packaging industry is to ensure'that the ultimate consumer receives a high quality, non-contaminated product. Whilethe use of the hermetically sealed container has substantially reduced the possibility of quality deterioration and contamination, certain closure designs currently used possess at least one objectionable feature. For example, when a corner sealing lugtype closure is attached to a container a void region occurs which is disposed between the closure skirt and container finish, outwardly of the sealing area. Because of the open area which exists between the container finish and the annular bead of the closure skirt, this void region is susceptible to insect infestation. Should this infestation be sufficiently prolonged in time, numerous undesirable characteristics will result, such as the forming of webs or larva production.

In addition to imparting an unwholesome appearance to the package, the web formation and larva production create contamination problems which are especially acute in the case of packaged comestibles and other preparations which are packaged in containers having a partial vacuum. This contamination results from the fact that when opening the sealed container and releasing the vacuum, air passes between the closure and glass; this air passage tends to blow any foreign matter attached to the internal skirt surface into the container.

Accordingly, it is the general object of this invention to provide for an improved closure and package that will maintain a product in a high quality, non-contaminated state.

It is another object of this invention to provide for a package that substantially reduces the possibility of insect infestation.

It is another object of this invention to provide for an improved package which substantially eliminates the void region between the glass finish and closure skirt, outwardly of the sealing zone.

In the achievement of the foregoing, and other objects,

' the invention contemplates providing the closure with an annular barrier member comprising a resilient, easily deformed plastic material; said barrier is attached to the internal surface of the closure skirt, outwardly of the sealing gasket, to substantially occupy the zone existing between the outer surface of the container and the inner surface of the closure.

The foregoing objects and others, will become apparent by reference to the drawing, of which:

FIGURE 1 is a fragmentary sectional view of a conventional lug-type closure assembled in sealing relation on a glass container;

FIGURE 2 is a fragmentary sectional view of a lugtype closure illustrating an embodiment of this invention;

FIGURE 3 is a fragmentary sectional view showing the closure of FIGURE 2 assembled in sealing relation with a glass container;

FIGURE 4 is a fragmentary sectional view of a sealed package illustrating another embodiment of this invention.

FIGURES 1, 2 and 3 of the drawings generally show a glass container 10 having a cylindrical neck 32 terminating in an upper annular rim 14 defining the open mouth 12 of the container. Immediately beneath and outwardly of the rim 14 is the concave sealing finish surface 34 of the container. Below this sealing finish surface and outwardly extending from the neck, the container is provided with lugs 36 for attaching engagement with a telescopic closure 15.

The closure 15 is formed of a metal, such as aluminum or tinplate, and comprises a top panel 16 and a depending annular attaching skirt 18. Said panel is deformed in an area adjacent its juncture with the skirt 18 to provide an annular recess 24 for receiving a conventional sealing gasket 22. This recess comprises a flat upper portion 17, an inwardly and downwardly extending wall 19 terminating at the periphery of the panel 16, and an outer wall 21 which slopes vertically and downwardly from its juncture with the flat portion 17. Said outer wall merges at its lower margin with the upper extremity of an inclined radial ledge 20; the lower extremity of said ledge merges with the skirt 18. The lower margin of the skirt 18 terminates in an inwardly disposed peripheral hollow head 30, said head being deformed at spaced intervals to form inwardly extending lugs 28 which mate with the corresponding lugs 36 of the container, whereby the closure is attached to the container.

outwardly disposed from sealing gasket 22 and the panel portion of the closure 16, the annular member 26 is preferably afiixed to be coextensive with the internal surface of the skirt existing beneath said sealing gasket. The means for applying and afiixing this member will subsequently be described in detail. Functionally, this member serves as the infestation barrier means and it substantially occupies the void which normally exists between the glass finish and the internal surface of an attached closure inwardly of the lower terminus of the closure skirt. Since the void no longer exists or because the former entrance to the void, that is the area in the non-lug sections between the annular head 30 and the glass finish, has been eliminated the susceptibility of the package to infestation and other adverse characteristics is substantially eliminated.

In a preferred embodiment the member 26 contains sufficient material such that when the closure is attached to the container, this member will be compressed and thereby substantially fill the void as previously stated.

FIGURE 4 shows an embodiment of this invention in conjunction with .a so-called top seal lug-type closure. The closure 15 is comprised of a top panel portion 16 and an attaching annular skirt 18, said closure being deformed in an area adjacent the juncture of the panel and skirt portions to form an upwardly extending annular recess 24 for receiving a suitable sealant 22. The sealant 22 may for example, be a flowed-in viscoelastic plastisol which is applied to the recess 24 in such manner that it contacts and seals upon the upper sealing surface or rim 14 of the container 10. Outwardly disposed of sealant 22 and inwardly of the peripheral bead 30, which exists at the lower margin of the closure skirt 18, is the void-filling annular barrier member .26.

The material comprising the barrier member of this invention is preferably a plastisol composition. This type of material essentially consists of dispersions of a synthetic resin and a non-volatile plasticizer. The resin is generally insoluble in the plasticizer, or at least has only limited solubility, at room temperature; when heated however, for example to about 200 F., solvation of the resin-plasticizer results. Further heating of this mass to 300-400 F will produce a solution which when cooled to room temperature produces a tough, permanent mass having desirable coating properties.

The synthetic resin to be used in suitable plastisols for this invention is preferentially polyvinyl chloride, although other thermoplastic materials, for example copolymers of vinyl chloride and vinyl acetate, copolymers of vinyl acetate, vinyl buterate, vinyl alcohols or vinylidene chloride may be used. Typical non-volatile plasticizers which are suitable for producing the plastisol are: 2 ethyl hexyl diphenyl phosphate; di-hexyl adipate; di-octyl sebacate; =acetyl tributyl citrate; di-2-et-hyl hexyl phthalate and diisooctyl phthalate.

In addition to the foregoing components, the plastisols preferably include a stabilizer and a foaming or blowing agent. The stabilizer is used to prevent degradation of the polymer resulting from either thermal or light ensitivity; materials suitable for this purpose include salts of the higher fatty acids, such as calcium or zinc stearate. Blowing or foaming agents are used to produce a cellular structured plastisol, more commonly termed a foamed plastisol; typical of the agents which may be used for this purpose are sodium bicarbonate, ammonium bicarbonate, or dinitrosopentamethylenetetramine. These cellular structural plastisols are particularly suitable for the practice of this invention because of the increased resiliency and softness which is imparted to the plastisol as a result of its having gaseous voids dispersed within the plastisol mass subsequent to the curing cycle. As stated previously, the barrier preferably contains sutficient material such that it is compressed to fill the void areas; consequently, the resiliency and softness of a foamed plastisol helps keep the increased removal torque of the closure, resulting from the addition of the glass contacting barrier to a minimum. Additionally, the foamed plastisols are preferred from an economic standpoint because the gaseous voids occupy space which would normally consist of plastisol itself if a non-foamed plastisol were to be used; consequently, there is a reduction in the amount of plastisol required and therefore less expense is incurred in the utilization of the foamed plastisol.

A suitable material, for the practice of this invention may be selected from several compositions commercially available and generally having the plastisol characteristics hereinbefore noted. As one preferred example, a commercially available foamed plastisol manufactured and sold by the Dewey & Almy Chemical Division of the W. R. Grace & Company of Chicago, 111., as their No. 3763, has been successfully used as the infestation barrier. In a preferred embodiment of this invention, the barrier is integrally attached as an annular member 26, having a substantial radial thickness, to the internal surface of the closure skirt existing outside the sealant 22 and inwardly of the lower terminus of the skirt in such manner that, when the closure is attached in sealing relation about the rim defining mouth of the container, the region between the closure skirt and the finish of the container is substantially occupied by the material constituting the barrier.

The barrier may be positioned within the closure, beneath the sealant or gasket, by any of several known techniques, such as inserting the barrier as a preformed ring, or forming and affixing it by known flow-in nozzle and spinning techniques. With the latter method, the uncured plastisol composition, for example the commercially available Dewey & Almy material previously noted, is deposited by means of a nozzle onto the internal skirt surface while rotating the closure on a suitable turntable device. Subsequent to the application of the uncured composition, continued spinning of the closure will force this deposited material to flow along the internal surface of the skirt, coating the entire skirt surface beneath the sealing gasket and, by minimizing the inherent arcuate pattern which results from the localized nozzle feed, producing a deposit having a relatively uniform radial thickness. The uncured composition is then transformed to a permanent mass by heating the coated closure to 300-400 F., holding it at that temperature for several minutes, and subsequently cooling to room temperature.

It is important that sufficient material be added to the internal surface of the closure such that, when the closure is in telescopic relation on the open mouth of the container, the material constituting the barrier will substantially fill the region, beneath the sealing gasket, existing between glass container finish and the closure skirt.

I claim:

1. An improved package comprising a container having a neck terminating in a rim defining an open mouth thereof and including a sealing surface, means formed exteriorly on said container neck adjacent said rim adapted to engage a closure for attaching the latter in covering said mouth, a closure having a top panel portion and an annular attaching skirt depending therefrom, means on said closure skirt for engaging said means formed exteriorly on said container neck when said closure is in telescopic relation about said neck whereby the closure is attached on said container, a gasket disposed intermediate said closure and said sealing surface for closing and sealing said container upon attachment of said closure, and an annular member aflixed to the internal surface of the closure skirt separate of the sealing gasket, and extending from said engaging means on said closure skirt substantially to said sealing gasket, said member being comprised of a resilient plastic composition for substantially filling the region existing between said container neck and closure when said closure and gasket are in their closing and sealing relation on said neck.

2. The package of claim 1, wherein said plastic composition is a foamed plastisol.

3. An improved package comprising a container having a generally cylindrical neck terminating in an upper annular rim defining the open mouth thereof and a corner sealing surface disposed adjacently beneath the rim and including means on said neck beneath said sealing surface adapted to engage a closure for attaching the latter to cover said open mouth, a closure having a top panel portion and an annular attaching skirt depending therefrom, means on said closure for engaging said means on said neck when said closure is in telescopic relation about the open mouth of said container, whereby the closure is attached thereto, a gasket positioned at the juncture of said closure panel and said depending skirt for engaging said corner sealing surface and thereby sealing said container upon attachment of said closure, and separate means attached on the interior of said closure skirt for substantially occupying the region disposed intermediate said closure skirt and said neck when said closure is attached thereto, said latter means extending from substantially the lower side of said gasket to said engaging means on said closure skirt.

4. The package of claim 3, wherein said means for substantially occupying the region disposed intermediate said closure skirt and container neck comprises an annular thermoplastic member of substantially uniform radial thickness.

5. The package of claim 4, wherein said thermoplastic member is a vinyl plastisol.

6. The package of claim 4, wherein said thermoplastic member is a foamed vinyl plastisol.

7. An improved package comprising a container having a generally cylindrical neck terminating in an annular rim defining the open mouth thereof, said neck having a sealing surface and including a plurality of outwardly extending lugs beneath said sealing surface to engage a closure for attaching the latter in covering said mouth, a closure having atop panel portion and an annular attaching skirt depending therefrom, said skirt terminating at its lower margin in an inwardly disposed hollow bead, said bead including peripherally spaced inwardly extending mating lugs engageable with said outwardly extending lugs when said closure is in telescopic relation about the open mouth of said container, whereby said closure is attached on said container, sealant means disposed intermediate said closure and said sealing surface for sealing said container upon attachment of said closure, and means afiixed within the closure downwardly of said sealant means for substantially filling the region intermediate said inwardly disposed hollow bead and said container neck when said closure is attached onto the latter.

8. The package of claim 7, wherein said means for substantially filling the region intermediate said inwardly disposed hollow bead and said container neck comprises an annular thermoplastic member.

9. The package of claim 8, wherein the thermoplastic member is a plastisol.

10. An improved package comprising a container having a rim defining the open mouth thereof and a sealing surface of arcuate formation disposed exteriorly of said rim and including a plurality of outwardly extending lugs formed exteriorly on said container beneath said sealing surface to engage a closure for attaching the latter in covering said mouth, a closure having a top panel portion and an annular attaching skirt depending therefrom, said skirt terminating at its lower margin in an inwardly disposed hollow bead, said bead being deformed at spaced intervals to form inwardly extending lugs which cooperate with said outwardly extending lugs when said closure is in telescopic relation about the open mouth of said container, whereby said closure is attached thereto, a gasket positioned at the juncture of said closure panel and said depending skirt engaging said sealing. surface and sealing said container upon attachment of said closure, and an annular infestation barrier member of foamed plastisol composition, said barrier member being afiixed to the internal surface of said skirt downwardly of said gasket and having a sufficient radial thickness to substantially occupy the region between said closure skirt and said container when said closure is attached thereto.

11. The package of claim 10*, wherein the foamed plastisol comprising the infestation barrier is a foamed polyvinyl chloride plastisol.

12. The package of claim 10, wherein the foamed plastisol comprising the infestation barrier is a foamed plastisol of a copolymer of vinyl chloride and vinyl acetate.

13. A closure for use in closing and sealing the mouth opening of a container comprising a circular top panel portion, an annular skirt and an intermediate annular portion connecting said top panel and said skirt as an integral closure shell, means formed on said skirt for engaging the container and attaching said closure onto the latter, a gasket disposed in said intermediate annular portion and carried with the closure, and an annular infestation barrier member attached to the lower annular interior region of said skirt upwardly of said engaging means and extending substantially along the interior surface of said skirt to be substantially adjacent the lower side of said gasket, said barrier member comprising a foamed plastisol composition whereby upon closure attachment to the container said barrier member is compressed and prevents entry of foreign matter into the region between said skirt and the outer surface of the container.

References Cited UNITED STATES PATENTS 2,339,702 1/1944 Isele 215- 2,348,014 5/1944 Mallard 215-43 2,365,737 12/1944 White 2154O 2,979,218 4/1961 Stover 21540 3,174,640 3/1965 Hart 2l540 3,202,307 8/1965 Rainer et al 2l540 XR DONALD F. NORTON, Primary Examiner, 

